The low-lying electronic state of FeC observed 3 460 cm−1 above X 3Δ2

Dispersed fluorescence spectra of FeC have been measured for the (I)3Δ3, 2 and (III)Ω=2 states observed in the region of 20 000–23 000 cm−1 of the LIF spectrum [W.J. Balfour, J. Chem. Phys. 103 (1995) 4046], and ωe(X 3Δ3)=862.9±6 cm−1 is determined. The (III)Ω=2 ← X 3Δ2 system has been reinvestigated with an LIF measurement at a 0.06 cm−1 resolution, and evidence for Σ–Π perturbation in the upper state is presented. In the DF spectra from (I)3Δ2 and (III)Ω=2, a new electronic state has been observed 3 460 cm−1 above X 3Δ2. The most probable candidate is 5Π2 arising from the configuration …8σ23π41δ29σ14π1.